Mitochondrial iron detoxification is a primary function of frataxin that limits oxidative damage and preserves cell longevity. Export

@article{citeulike:2996194, abstract = {Friedreich ataxia is a severe autosomal-recessive disease characterized by neurodegeneration, cardiomyopathy and diabetes, resulting from reduced synthesis of the mitochondrial protein frataxin. Although frataxin is ubiquitously expressed, frataxin deficiency leads to a selective loss of dorsal root ganglia neurons, cardiomyocytes and pancreatic beta cells. How frataxin normally promotes survival of these particular cells is the subject of intense debate. The predominant view is that frataxin sustains mitochondrial energy production and other cellular functions by providing iron for heme synthesis and iron-sulfur cluster (ISC) assembly and repair. We have proposed that frataxin not only promotes the biogenesis of iron-containing enzymes, but also detoxifies surplus iron thereby affording a critical anti-oxidant mechanism. These two functions have been difficult to tease apart, however, and the physiologic role of iron detoxification by frataxin has not yet been demonstrated in vivo. Here, we describe mutations that specifically impair the ferroxidation or mineralization activity of yeast frataxin, which are necessary for iron detoxification but do not affect the iron chaperone function of the protein. These mutations increase the sensitivity of yeast cells to oxidative stress, shortening chronological life span and precluding survival in the absence of the anti-oxidant enzyme superoxide dismutase. Thus, the role of frataxin is not limited to promoting ISC assembly or heme synthesis. Iron detoxification is another function of frataxin relevant to anti-oxidant defense and cell longevity that could play a critical role in the metabolically demanding environment of non-dividing neuronal, cardiac and pancreatic beta cells.}, address = {Department of Pediatric, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.}, author = {Gakh, O. and Park, S. and Liu, G. and Macomber, L. and Imlay, J. A. and Ferreira, G. C. and Isaya, G.}, citeulike-article-id = {2996194}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/16371422}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=16371422}, day = {1}, issn = {0964-6906}, journal = {Human molecular genetics}, keywords = {frda, yeast}, month = {February}, number = {3}, pages = {467--479}, posted-at = {2008-07-12 16:11:24}, priority = {2}, title = {Mitochondrial iron detoxification is a primary function of frataxin that limits oxidative damage and preserves cell longevity.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/16371422}, volume = {15}, year = {2006} }

TY - JOUR ID - citeulike:2996194 L3 - citeulike-article-id:2996194 N2 - Friedreich ataxia is a severe autosomal-recessive disease characterized by neurodegeneration, cardiomyopathy and diabetes, resulting from reduced synthesis of the mitochondrial protein frataxin. Although frataxin is ubiquitously expressed, frataxin deficiency leads to a selective loss of dorsal root ganglia neurons, cardiomyocytes and pancreatic beta cells. How frataxin normally promotes survival of these particular cells is the subject of intense debate. The predominant view is that frataxin sustains mitochondrial energy production and other cellular functions by providing iron for heme synthesis and iron-sulfur cluster (ISC) assembly and repair. We have proposed that frataxin not only promotes the biogenesis of iron-containing enzymes, but also detoxifies surplus iron thereby affording a critical anti-oxidant mechanism. These two functions have been difficult to tease apart, however, and the physiologic role of iron detoxification by frataxin has not yet been demonstrated in vivo. Here, we describe mutations that specifically impair the ferroxidation or mineralization activity of yeast frataxin, which are necessary for iron detoxification but do not affect the iron chaperone function of the protein. These mutations increase the sensitivity of yeast cells to oxidative stress, shortening chronological life span and precluding survival in the absence of the anti-oxidant enzyme superoxide dismutase. Thus, the role of frataxin is not limited to promoting ISC assembly or heme synthesis. Iron detoxification is another function of frataxin relevant to anti-oxidant defense and cell longevity that could play a critical role in the metabolically demanding environment of non-dividing neuronal, cardiac and pancreatic beta cells. IS - 3 JF - Human molecular genetics SN - 0964-6906 AD - Department of Pediatric, Mayo Clinic College of Medicine, Rochester, MN 55905, USA. EP - 479 TI - Mitochondrial iron detoxification is a primary function of frataxin that limits oxidative damage and preserves cell longevity. VL - 15 SP - 467 KW - frda KW - yeast AU - Gakh, O AU - Park, S AU - Liu, G AU - Macomber, L AU - Imlay, JA AU - Ferreira, GC AU - Isaya, G PY - 2006/02/01/ UR - http://view.ncbi.nlm.nih.gov/pubmed/16371422 ER -